Overload circuit breaker

ABSTRACT

An overload circuit breaker utilizes a stationary member having a first contact element located on its surface and a movable resilient member having a sacrificial contact element located on its surface. A resilient bimetallic member is operable as a toggle to control the movable member. An electrical terminals means is connected such that an electrical circuit is formed through the first and second contact elements as well as through the resilient bimetallic member and the movable resilient member. The resilient bimetallic member and movable resilient member move with a snap-action from the first stable position to the second stable position upon a flow of a predetermined electrical current through the electrical circuit, thereby opening the first contact element and the sacrificial contact element and breaking the electrical circuit. A reset element actuable from a first position to a second position is provided to move the first resilient bimetallic member from the second stable position and back to the first stable position. The reset element is adapted such that the first contact element and the sacrificial contact element do not close until the reset element returns to its first position. In some embodiments, an ambient temperature compensating element is also provided for the overload circuit breaker.

United States Patent [191 Summe et al.

June 5, 1973 OVERLOAD CIRCUIT BREAKER Filed: July 13, 1972 Appl. No.: 271,603

US. Cl. ..337/91, 337/345, 337/348 Int. Cl. ..H01h 61/00 Field oi Search ..337/345, 343, 348,

[56] References Cited UNITED STATES PATENTS 6/1951 Kohl .Q. ..337/343 2,910,561 10/1959 Freyetal. ..337/88 Primary Examiner-Harold Broome 'AttorneyJack C. Berenzweig [57] ABSTRACT An overload circuit breaker utilizes a stationary member having a first contact-element located on its surface and a movable resilient member having a sacrificial contact element located on its surface. A resilient bimetallic member is operable as a toggle to control the movable member. An electrical terminals means is connected such that an electrical circuit is formed through the first and second contact elements as well as through the resilient bimetallic member and the movable resilient member. The resilient bimetallic member and movable resilient member move with a snap-action from the first stable position to the second stable position upon a flow of a predetermined electrical current through the electrical circuit, thereby opening the first contact element and the sacrificial contact element and breaking the electrical circuit. A reset element actuable from a first position to a second position is provided to move the first resilient bimetallic member from the second stable position and back to the first stable position. The reset element is adapted such that the first contact element and the sacrificial contact element do not close until the reset element returns to its first position. In some embodiments, an ambient temperature compensating element is also provided for the overload circuit breaker.

11 Claims, 13 Drawing Figures Pmmd June 5,1913 3,737,825

3 Shuts-Shut 2 Patented Junas, 1973 FIG. 9

3 Sheets-Shut :5

f 1 OV'ERLOAD CIRCUIT BACKGROUNDOF THE INVENTION The .presentinvention relates to circuit breakers and more particularly, to electrical circuit breakers which are adapted to protect electronic appliancesarid-"the tered-in the use of conventionalcircuit breakerswher'e there is a failure to have incorporated th'e'rein a means for accurate ambient; temperature compensation. While. most'electronic devicesoperate at room temperatures of 65-'85 F., the ambient't'ernper'atu're of the environment can go ashigh as l50 F. Underth'ese elevated ambient temperatures, unless the circuit breaker is properly compensated, the trip "point of the breakermay be substantially shifted so thata false tripping or opening of the break'ercontacts may occur. The present invention overcomesthis difficulty.

It has also been found advantageous'to utilize a resetable circuit breaker, especially when used in television receivers. The resetable *circuit breaker such as that provided by the 'instantinvention provides that th'e'circuit may only be closed after theoperator has removed his hand from the reset'r'nechanism. This is exceptionally important to provide operator protection and circuitry protection within'the television receiver.

, Heretofore, several prior art circuit breakers have been devised to overcome these problems. However, these prior art circuit breakers have not proved satisfactory under all conditions of service. One such prior art circuit breaker is described in U.S. Pat. No. 2,910,561, issued to C. F."Frey et al. on-ct. 27, 1959. The circuit breaker described in theFrey patent has not-proved entirely satisfactory'sinceunder conditions of high current, such as 50 amps, the bimetal element 24 would anneal due to its relativelysmall'dirnensions. In addition, under conditions of approximately 150 amps the elements of the circuit breaker-would split apart and float within the housing thereby'creating the danger of uncontrolled short'circuitsuFurthermore, "any accidental impact on thereset button 40would tend to distort the housing as well as the member thereby inadvertently changing the break point for the circuit breaker. An additional limitation in the Frey circuit breaker arises from the fact that as current through the circuit breaker increases; the pressure between the contacts decreases thereby giving rise to the possibility of an unacceptable performance of thecircuit breaker just prior to the break point.

Two similar prior art circuit breakers are disclosed in U.S. Pat. Nos. 3,038,047 and 3,234,348, issued to J. F. Marquis and F. B. Desiofrespectively, on June 5, 1962 and'Feb. 8, 1966. Each offthese circuit breakers utilize a pair of latching contacts. These contacts are not advantageous since they are subject to pitting. It has been recognized that when theqcontactsbecome pitted, the

break point for the circuitbreaker changes. Furthermore, the pitting of the contacts prevents using a low ratio of'break currentto hold current. Lastly, under high current conditions, the switch member 41 of the Desio patentand the switch member 20 ofthe Marquis patent would tend to obtain a reverse bend and if the breaker "were to fail, this reverse bend would tend to cause the circuit breaker to fail in a closed position rather than in an opened position.

A third type of prior art switch is disclosed in U.S. Pat. No. 2,558,219, issued to E. F. Kohl on June 26, 1951. lnthis switch, no current is passed through the toggle "member 1 or through the C-spring 7. This switch is "designed to momentarily make and break a switch contact. While this switch bears certain similarities to the invention disclosed below, its method of operation is entirely different.

SUMMARY OF THE INVENTION The general purpose of this invention is to provide an electrical circuit breaker which embraces all of the advantages of similarly employed circuit breakers and possesses none of the aforedescrib'ed limitations. T0 attain this, the present invention contemplates several unique overload'circuit breakers. Each of these circuit breakers employes a bimetallic toggle member which ensures that the pressure between the contacts increases prior to the break point of the circuit breaker thereby ensuring greater reliability. In addition, each of the toggle members is designed. so as to eliminate the possibility of being annealed under high current conditions. Furthermore, a sacrificial contact element is empl'oiyed to overcome the possibility of the contact elements fusing or welding together. Lastly, some of the preferred embodiments of the invention provide for ambient temperature compensation.

It is, therefore, an object of the present invention to provide a circuit breaker wherein the contact pressure is increased prior to opening, which is accurately compensated for ambient temperature changes and which is not subjected to contactsticking or welding.

Another object is to provide a resetable overload circuit'breaker wherein the circuit cannot be made while the reset spring or button is depressed.

A further object of the invention is to provide a circuitbreaker which may be utilized as a controlled relay.

Still another object of the invention is to provide an overloadcircuitbreaker which is simple in construction, and reliable in operation.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS I of FIG. 1

FIG. 5 is a sectional view of the circuit breaker of FIG. 1 showing the contacts in their open position.

FIGS. 6 and 7 are diagrammatic views, with parts removed, of the circuit breaker of FIG. 1, showing the contacts in their closed position and open position, respectively.

FIG. 8 is a sectional view of a second preferred embodiment of the invention showing the contacts in their normally closed position.

FIG. 9 is a top plan view of the toggle member used in the circuit breaker of FIG. 8.

FIGS. 10 and 11 are diagrammatic views, with parts removed, of the circuit breaker of FIG. 8, showing the contacts in their closed and open position, respectively.

FIG. 12 is a diagrammatic view of one of the circuit breakers of the present invention being utilized as a controlled relay.

FIG. 13 is a sectional view taken along the lines 13-13 of FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIGS. 1-4 an overload circuit breaker 10 which illustrates a first embodiment of the invention. The overload circuit breaker 10 includes a stationary member 12 which has a first end 14 and a second end 16. In the preferred embodiment, the stationary member 12 is substantially planar and is manufactured from any suitable conducting material. The first end 14 of the stationary member 12 is connected to an insulator 18 in a conventional manner. As will become evident below, the insulator 18 may comprise a single insulator having slots therein to accept the various members or may comprise a plurality of insulators which are fastened together by a suitable fastening means 17. Located on the surface of the stationary member 12 is contact element 20. The contact element 20, in the preferred embodiment, may comprise any suitable conducting material and may be integral with the stationary member 12 or may be affixed thereto in conventional manner.

The overload circuit breaker 10 further comprises a resilient member 22 having a first end 24 and a second end 26. The first end 24 of the resilient member 22 is secured within the insulator l8 and is spaced apart from the stationary member 12. A sacrificial contact element 36 is located on the upper surface of the resilient member 22. In the preferred embodiment, the contact element 36 is embossed on the surface of the resilient member 22.

Resilient member 22 is manufactured from a metal having conventional current carrying capability for normal currents. However, the melting point and thermal conductivity of the metal and the shape of the emboss (element 36) are such that under large current surges, the high current density will cause element 36 to become molten in the area where it contacts element 20. Because the contact element 36 becomes molten at high current levels, the contact element 36 will not become welded nor will it fuse to the other contact element 20. This type of contact is known as a sacrificial contact.

The overload circuit breaker 10 further comprises a resilient bimetallic toggle member 50. As can be seen from FIG. 2, the resilient bimetallic toggle member 50 comprises a first leg 54 and a second leg 56. The first and second legs 54 and 56 are electrically connected at the second end 58 of the resilient bimetallic toggle member 50. However, the first leg 54 and the second leg 56 are not electrically connected at the first end 57 of the bimetallic toggle member 50. The bottom surface 52 of the bimetallic resilient toggle member 50 comprises a high expansion sidewhile the top surface 53 comprises a low expansion side. The resilient bimetallic toggle member 50 in the preferred embodiment comprises a relatively large cross-sectional and surface area. These large areas serve to dissipate heat which is caused by large current surges and also serve as a thermal reservoir thereby preventing circuit breaker 10 from being subject to false openings which might be caused by short duration transients which are not harmful to the circuit being protected.

As can be seen from FIGS. 1 and 3, the first leg 54 is placed in contact with the first end of the resilient member 22. The first end of the second leg 56 of the resilient bimetallic toggle member 50 is insulated from the resilient member 22 by an insulator 19. An electrical terminal means 40a which is part of stationary member 12 and an electrical terminal means 40b which is connected to the second leg 56 of the resilient bimetallic toggle member 50 are provided. An electrical circuit is, therefore, formed through the terminal means 40b, through the second leg 56 of the bimetallic toggle member 50, through the first leg 54 of the bimetallic toggle member 50, through the resilient member 22, the contact elements 36, 20, and finally out through the stationary member 12 and the terminal means 40a.

Referring again to FIG. 1, a resilient C-spring 60 is mounted between the second end 26 of the resilient member 22 and the end 58 of the resilient bimetallic toggle member 50. The C-spring 60 is provided to maintain the resilient bimetallic toggle member 50 in a first stable position and to maintain the resilient member 22 in a first stable position as shown in FIG. 1. When the resilient bimetallic toggle member 50 and the resilient member 22 are in their first stable positions, the contact elements 20 and 36 are closed. The C spring 60 may be made from any resilient material and it will be recognized that its shape may be changed and need not necessarily comprise a C shape. The C-spring 60 is electrically insulated from the bimetallic toggle member 50 by an insulating member placed on the end 58. If ambient temperature compensation is desired in the circuit breaker 10, the C-spring 60 may be made from a bimetallic material and the high expanding side of the bimetallic material would be placed on the inner surface 62 of the C-spring 60. It should be noted that as the ambient temperature increases, the C-spring 60 will expand thereby counteracting the expansion of the bimetallic element 50 due to the increasing ambient temperature thereby eliminating the possibility of an inadvertant opening of the contact elements 20 and 36.

When'the contact elements 20 and 36 are in their closed position, as shown in FIGS. 1 and 6, the bimetallic toggle member 50 is in its first stable position. If an overload current condition occurs, the bimetallic toggle member 50 would bend and move upward over center to a second stable position and the resilient member 22-would move downward with a snap action to a second stable position thereby compressing the C-spring 60 and causing the contact elements 20 and 36 to separate when the toggle. member 50 goes over center as shown in FIGS. 5 and-7L The bimetallic toggle member 50 reacts in this manner since during an overload condition, excessive heat is generated and this causes the high expansion side of i the resilient bimetallic toggle member 50 to expand at 'occurs is commonly referred to as the break point or set point for the circuit breaker.

The contact elements and 36 remain separated until the resilient bimetallic toggle member 50 is returnedto its first stableposition. A reset element'38is provided for this purpose. The reset element shown in FIG. 1 is adapted to move from a first position, as shown in FIG. 1, to a second position. When his desired to reset the overload circuit breaker 10, the reset element 38 is depressed downwardly to a second position. A pair of shoulders 39 (FIG. 4) on the reset elethem 38 contacts the legs 54 and 56 of the "resilient bimetallic toggle member 50 causingtheiresilient bimetallic toggle member 50 to snap backto its first stable position'thereby compressing the C-spr ing 60 and moving the second end 26 of the resilient member 22 upwardly thereby closing the contact elements 20 and It will be noted that silong as the "reset element 38 is depressed, the bridge 38a between the shoulders 39 will prevent the movable member 22 from snapping back to its first stable position and this will prevent the contact elements 20 and 36 from closing. When the resetelement 38 is released, thereby enabling the reset element 38 to go back to its first position, t'he contact elements 20 and 36 will then close. By requiring the 're'set'element 38 to ret urn to its first position, prior to the closing of the contact elements 20 and 36, thisassures thatthe operator will not reclose the circuit until his hand has been remoyed thereby adding to the safety of the overload circuit breaker 10. o

A s'can be seen in FIGS. l-S thecircuit breaker It) further comprises a base member 70 the resilient elements described above are mounted: The

base member 70 comprises a convcntio'nal insulator material through which the terminal means QOaI and 40b extend. An extensipn 72 providedto serve asa stop for button 38 soth'at the resilient members are not damaged when button is subjected to impact. Extension 72 also limitsthedownward travel of resilient member 22 when the contacts are open. Extension 72 further serves to hold resilient member 22 ina fixed position so that shoulders on button 38 will push legs 54 and 56of resilient bimetallic toggle member 50. over center with respect to the position of resilient member 22' and allow circuit breaker 10 to be reset. A pai r of extensions 74 are provided to limit the downward travel of toggle member-:50 and thereby assure that the contacts 36 and 20 remain closed when circuit breaker 10is exposed to cold ambient temperatures.

Lastly, a housing 76 is placed over the base member to protect the entire circuit breaker 10. It will be recognized that the overload circuit breaker 10, as well as the alternative circuit breaker described below, may be placed within any other suitably shaped housing and, furthermore, mayalso be utilized without a housing if it is so desired.

Referring now to FIGS. 8-11, an overload circuit breaker is shown which is similar to the overload circuit breaker 10. In this embodiment, a resilient bimetallic toggle member 150 (FIG. 9) comprises a bimetallic construction having the high expanding side on the lower surface 152. A resilient member 122 is provided and is insulated from the toggle member 150 by an insulator 119. The resilient member 122 comprises a conductive material but is not bimetallic. A stationary member 112 is also provided. As before, a pair of contact elements and 136 are provided on the lower surface of the stationary member 112 and the upper surface of the resilient element 122, respectively. A C-spring 160 is provided which maintains the contact elements 120 and 136 in their closed position. A pair of electrical terminals 140a and 14% are connected respectively to the stationary member 112 and the resilient bimetallic toggle member 150. When the electrical terminals 140a and 140k are connected to a source of current, an electrical circuit is provided through the resilient bimetallic toggle member 150, the conductive C-spring 160, the resilient member 122, the contact elements 136 and 120, and the stationary member 112; As shown in FIGS. 10 and 11, when the resilient bimetallic toggle member is in its first stable condition, the contact elements 120 and 136 are closed. An overload of current flowing through the overload circuit breaker 110 would cause the resilient bimetallic toggle member 150 to move upward, thereby compressing the C -spring 160. When the C-spring was compressed enough, the resilient bimetallic toggle member 150 would move over its center position and shift into a second stable position. The C-spring 160 would then push down the resilient member 122 thereby opening the contact elements 120 and 136. A reset element 138 is also provided to reset the contacts in a manner similar to that described above in connection with circuit breaker 10. As mentioned previously, the C-spring 160 may be made from anyresilient material and it will be recognizedthat its shape may be changed and need not necessarily comprise a C shape.

If .it is desired to compensate the overload circuit breaker 110 for changes in ambient temperature, the C-spring 160. may utilize a bimetallic construction having the high expansion side along the upper surface 162. However, it will then be necessary to insulate the C-spring 160 by insulating members 175, from the bimetallic toggle member 150 and provide a flexible conductor 176 as a current bypass path. In this instance, a current path is provided from the terminals 140a and 14017 through the resilient bimetallic toggle member 150, the flexible conductor 176, the resilient element 122, the contact elements 136 and 120, and the stationcreasing contact pressure prior to the break point, sacrificial contact element 136 to prevent welding, and relatively large cross-sectional and surface areas on toggle member 50 to prevent annealling by dissipating large amounts of heat which is caused by large current surges and also serve as a thermal reservoir preventing false openings due to short duration transients.

Referring now to FIG. 12, there is shown a relay control 210. It will be recognized that the relay control 210 is very similar to the overload circuit breaker 10 disclosed in FIGS. 1-7. The relay control 210 comprises a stationary member 212 and a movable resilient member 222 which are connected via electrical terminals 280 and 281 to any electrical circuit. Located on the surface of the stationary member 212 is a contact element 220 and similarly, a contact element 236 is located in the movable member 222. A toggle member 250 and a C-spring 260 are provided and serve the same function as their equivalent members shown in FIGS. 1-7.

Insulator 282 has been added between movable member 222 and first leg 254 of bimetallic toggle member 250. Electrical terminal 240a is placed in contact with the first leg 254. The second leg 256 of bimetallic toggle member 250 is insulated from electrical terminal 240a by insulator 219. Electrical terminal 240b is connected to second leg 256. The electrical circuit formed through terminal 240b, through the second leg 256 of bimetallic toggle member 250, through the first leg 254 of bimetallic toggle member 250, and finally out through terminal 240a becomes the control circuit. If it is desired to open the contact elements 220 and 236, it is only necessary to place a predetermined current through the control circuit which will then cause the resilient bimetallic toggle element 250 to move from its first stable position to its second stable position thereby opening the contacts 220 and 236.

It will be recognized by one skilled in the art that many other overload control circuits may be modified to act as a relay in the same manner.

Obviously, many modifications and variations of the present invention are possible in light of the above teaching and it should be understood that the foregoing disclosure relates only to preferred embodiments of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

What is claimed is:

1. An overload circuit breaker comprising:

an insulating means;

a first snap action resilient bimetallic member operable between a first stable position and a second stable position wherein said resilient bimetallic member comprises a first leg and a second leg spaced apart from said first leg wherein said first leg and said second leg are electrically insulated from each other at a first end and are electrically connected at a second end and wherein said first end is secured to said insulating means;

a first resilient conducting member comprising a first end and a second end wherein said first end is electrically connected to said first leg of said first bimetallic member;

a stationary conducting planar member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced tion whereby said first and second contact elements are electrically closed against each other;

electrical terminal means connected to said second leg of said first bimetallic resilient member and connected to said stationary conducting member whereby when said first and second contact elements are closed against each other an electrical circuit is provided through said first resilient bimetallic conducting member, said first resilient conducting member, said first and second contact elements, and said stationary conducting member and whereby said first resilient bimetallic member moves with a snap action to said second stable position upon a flow of a predetermined electrical current through said electrical circuit thereby opening said first and second contact elements and breaking said electrical circuit; and

reset means actuable from a first position to a second position to move said resilient bimetallic member from said second stable position to said first stable position wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position.

2. The overload circuit breaker of claim 1 wherein said second resilient member comprises a bimetallic conducting member and acts as an ambient temperature compensating means.

3. The overload circuit breaker means of claim 2 wherein said second resilient member comprises a C- spring and wherein said C-spring is compressed when said first bimetallic member goes from said first stable position to said second stable position.

4. The overload circuit of claim 3 wherein said reset means comprises:

a reset means which is actuable from said first position to said second position whereby said reset means in said second position causes said first bimetallic member to move from said second stable position to said first stable position thereby compressing said second resilient member and wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position. 5. The circuit breaker of claim 4 further comprising a base means operably associated with said first bimetallic member and a limit means located on said base means to prevent excessive downward travel of said first resilient conducting member when said reset means is actuated from said first position to said second position and said limit means also providing reset button restraint to eliminate impact damage.

6. The circuit breaker of claim 1 wherein said second contact element comprises a sacrificial contact. 7. An overload circuit breaker comprising: an insulating means;

afirst snap action resilient bimetallic toggle member operable between a first stable position and a second stable positionwherein said resilient bimetallic member is planar and comprises a first end and a second end and wherein said first end is secured to said insulating means;

stationary conducting member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said first resilient bimetallic member;

first resilient conducting planar membercomprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said stationary conductingimember; I

a first contact element located on the surface of said stationary conducting member;

second contact element located on thesurface of said first resilient conducting member;

second resilient conducting memberconnectedbetween said second end of said first bimetallic toggle member and said second end ofsaid first resilient conducting member wherein said second resilient conducting member maintains said first resilient bimetallic member in said first stable position whereby said first and said second contact elements are electrically closed against each other;

electrical terminal means connected to said first bireset means actuable from a first position to a second 8. second resilient member comprises a C-spring and wherein said Crspring is compressed when said firstbimetallic member goes from said firststable position to said second stable position.

position to move said-first resilient bimetallic member from said second stable position to said first stable position wherein said reset means prevents said first andsecondcontact elements from closing until said reset means returns to said first position. The overload circuit means ofclaim 7 wherein said 9. The overload circuit of claim 8 whereinsaid reset means comprises:

reset means which ,is' actuable from-said first position to said secondposition whereby said reset means in said secondpositionvcausestsaid first bi.- metallic member to move from saidsecondstable position .to said firstflstable position thereby com.- pressing said secondzresilient memberland wherein said reset means prevents saidfirst and second com tact elements from closing until said reset means returns to said first position.

10. An overload circuit breaker comprising:

an insulating means;

a first snap action resilient bimetallic toggle member operable between a first stable position and a second stable position wherein said resilient bimetallic member is planar and comprises a first end and a second end and wherein said first end is secured to said insulating means;

stationary conducting member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said first resilient bimetallic member;

resilient conducting planar member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said stationary conducting member;

stationary conducting member;

second contact element located on the surface of said resilient conducting member;

second resilient bimetallic conducting member connected between said second end of said first-bimetallic toggle member and said second end of said resilient conducting member andelectrically insulated therefrom wherein said second resilient bimetallic conducting member acts as an ambient temperature compensating means and maintains said first resilient bimetallic member in said first stable position whereby said first and said second contact elements are electrically closed against each'other; flexible conductor means for electrically connecting ient conducting planar member;

electrical terminal means connected to said first bimetallic resilient member and connected to said stationary conducting member whereby when said first and second contact elements are closed against each other an electrical circuit is provided through said first resilient bimetallic member, said flexible conductor means, second end of first resilient member, said first and second contact elements, and said stationary conducting member and whereby said first resilient bimetallic member moves with a snap action to said second stable position upon a flow of a predetermined electrical current through said electrical circuit thereby opening said firstvand second contact elements and breaking said electrical circuit; and

reset means actuable from a first position to a second position to move said resilient bimetallic member from-said second stable position to said first stable position wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position.

11. A relay control for an electrical circuit comprismg: l

a first, second and third insulating means;

a first snap action resilient bimetallic member operable between a first stable position and a second stable position wherein said resilient bimetallic member comprises a first leg and a second leg spaced apart from said first leg wherein said first leg and said second leg are electrically insulated from each other at a first end and are electrically connected at a second end;

a first resilient conducting member comprising a first end and a second end wherein said first end is electrically insulated from said first bimetallic member by said first insulating means;

afirst contact element located on the surface of said said first resilient bimetallic member to said resil-' stationary conducting member comprising a first end and a second end wherein said first end is secured to said second insulating means and is spaced apart from said first resilient conducting member;

a first contact element located on the surface of said first electrical terminal means connected to said first leg of said first bimetallic resilient member and insulated from said stationary conducting member by said first insulating means;

second electrical terminal means connected to said second leg of said first bimetallic resilient member and insulated from said first leg by said third insulating means;

source of control current connected to said first and second electrical terminal means wherein said control current causes heat in said first resilient bimetallic member and wherein said heat causes said first resilient bimetallic member to move to said second stable position thereby opening said first and second contact elements and breaking said electrical circuit; and

reset means actuable from a first position to a second 1 position to move said first resilient bimetallic member from said second stable position to said first stable position wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position.

I UNITED STATES PATENT OFFICE CERTIFlCATE 0F CORRECTION Patent-No ,8 f c n I Dated Junes, 1,973

Inventor) Richard D. Summe and Everett H. Vannoy it is certified that error appears in the above-identified patent I and that said Letters Patent are hereby corrected as shown below:

Co1umn 8, line'38, c1e1ete "conducting",

f Column 8, line/l5, after "Circuit" insert -breaker-.

Column 9 line 50 after circuit insert -breake rr I Column 9, line 55,. afterflcircuit'? insert ,b reaker-.

Column 10, line 19, delete-"conducting".

Add the following claims:

"12. The circuit breaker of Claim 7 wherein said second contact element comprises a sacrificial contact -13. The circuit breakerof'Claim 10 wherein said second Contact eleme' nt;comprises a sacrificialcontact." i

s "14. The relay control of Claim 11 wherein said second contact ele'r'nentcomprises asaclr'ificial contact-,-

Signed andfsealed thisl8th day of December 1973. v

v Attesi'.

EDWARDMJLETCHERJR. [RENE D}; TEGTMIEYEIR Attesting Officer Acting CommissionerO in-Patents Patent No" 737,825 Dated June 5, 1973 lnventofls) Richard D Summe and Everett H. Vannoy r is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, line 58, delete conducting".

Column 8, line 45, after "circuit" insert breaker-.

Column 9, line 50, after "circuit" insert "breaker".

Column 9, line 55, after "circuit" insert -breaker. Column 10, line 19, delete "conducting".

Add the following claims:

-l2. The circuit breaker of Claim 7 wherein said second contact element comprises a sacrificial contact.

--l3. The circuit breaker of Claim 10 wherein said secon contact element comprises a sacrificial cont-act.-

-l4. The relay control of Claim 11 wherein said second contact element comprises a sacrificial contact.

Signed and sealed this 18th day of December 1975.

(SEAL) l Attes EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer Acting Commissioner of. Patents 

1. An overload circuit breaker comprising: an insulating means; a first snap action resilient bimetallic member operable between a first stable position and a second stable position wherein said resilient bimetallic member comprises a first leg and a second leg spaced apart from said first leg wherein said first leg and said second leg are electrically insulated from each other at a first end and are electrically connected at a second end and wherein said first end is secured to said insulating means; a first resilient conducting member comprising a first end and a second end wherein said first end is electrically connected to said first leg of said first bimetallic member; a stationary conducting planar member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said first resilient conducting member; a first contact element located on the surface of said stationary conducting member; a second contact element located on the surface of said resilient conducting member; a second resilient member connected between said second end of said first bimetallic member and said second end of said first resilient conducting member and electrically insulated therefrom wherein said second resilient member maintains said first resilient bimetallic member in said first stable position whereby said first and second contact elements are electrically closed against each other; electrical terminal means connected to said second leg of said first bimetallic resilient member and connected to said stationary conducting member whereby when said first and second contact elements are closed against each other an electrical circuit is provided through said first resilient bimetallic conducting member, said first resilient conducting member, said first and second contact elements, and said stationary conducting member and whereby said first resilient bimetallic member moves with a snap action to said second stable position upon a flow of a predetermined electrical current through said electrical circuit thereby opening said first and second contact elements and breaking said electrical circuit; and reset means actuable from a first position to a second position to move said resilient bimetallic member from said second stable position to said first stable position wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position.
 2. The overload circuit breaker of claim 1 wherein said second resilient member comprises a bimetallic conducting member and acts as an ambient temperature compensating means.
 3. The overload circuit breaker means of claim 2 wherein said second resilient member comprises a C-spring and wherein said C-spring is compressed when said first bimetallic member goes from said first stable position to said second stable position.
 4. The overload circuit of claim 3 wherein said reset means comprises: a reset means which is actuable from said first position to said second position whereby said reset means in said second position causes said first bimetallic member to move from said second stable position to said first stable position thereby compressing said second resilient member and wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position.
 5. The circuit breaker of claim 4 further comprising a base means operably associated with said first bimetallic member and a limit means located on said base means to prevent excessive downward travel of said first resilient conducting member when said reset means is actuated from said first position to said second position and said limit means also providing reset button restraint to eliminate impact damage.
 6. The circuit breaker of claim 1 wherein said second contact element comprises a sacrificial contact.
 7. An overload circuit breaker comprising: an insulating means; a first snap action resilient bimetallic toggle member operable between a first stable position and a second stable position wherein said resilient bimetallic member is planar and comprises a first end and a second end and wherein said first end is secured to said insulating means; a stationary conducting member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said first resilient bimetallic member; a first resilient conducting planar member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said stationary conducting member; a first contact element located on the surface of said stationary conducting member; a second contact element located on the surface of said first resilient conducting member; a second resilient conducting member connected between said second end of said first bimetallic toggle member and said second end of said first resilient conducting member wherein said second resilient conducting member maintains said first resilient bimetallic member in said first stable position whereby said first and said second contact elements are electrically closed against each other; electrical terminal means connected to said first bimetallic resilient member and connected to said stationary conducting member whereby when said first and second contact elements are closed against each other, an electrical circuit is provided through said first resilient bimetallic member, said second resilient member, second end of first resilient member, said first and second contact elements, and said stationary conducting member and whereby said first resilient bimetallic member moves with a snap action to said second stable position upon a flow of a predetermined electrical current through said electrical circuit thereby opening said first and second contact elements and breaking said electrical circuit; and reset means actuable from a first position to a second position to move said first resilient bimetallic member from said second stable position to said first stable position wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position.
 8. The overload circuit means of claim 7 wherein said second resilient member comprises a C-spring and wherein said C-spring is compressed when said first bimetallic member goes from said first stable position to said second stable position.
 9. The overload circuit of claim 8 wherein said reset means comprises: a reset means which is actuable from said first position to said second position whereby said reset means in said second position causes said first bimetallic member to move from said second stable position to said first stable position thereby compressing said second resilient member and wherein said reset means prevents said first and second contact elements from clOsing until said reset means returns to said first position.
 10. An overload circuit breaker comprising: an insulating means; a first snap action resilient bimetallic toggle member operable between a first stable position and a second stable position wherein said resilient bimetallic member is planar and comprises a first end and a second end and wherein said first end is secured to said insulating means; a stationary conducting member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said first resilient bimetallic member; a resilient conducting planar member comprising a first end and a second end wherein said first end is secured to said insulating means and is spaced apart from said stationary conducting member; a first contact element located on the surface of said stationary conducting member; a second contact element located on the surface of said resilient conducting member; a second resilient bimetallic conducting member connected between said second end of said first bimetallic toggle member and said second end of said resilient conducting member and electrically insulated therefrom wherein said second resilient bimetallic conducting member acts as an ambient temperature compensating means and maintains said first resilient bimetallic member in said first stable position whereby said first and said second contact elements are electrically closed against each other; flexible conductor means for electrically connecting said first resilient bimetallic member to said resilient conducting planar member; electrical terminal means connected to said first bimetallic resilient member and connected to said stationary conducting member whereby when said first and second contact elements are closed against each other an electrical circuit is provided through said first resilient bimetallic member, said flexible conductor means, second end of first resilient member, said first and second contact elements, and said stationary conducting member and whereby said first resilient bimetallic member moves with a snap action to said second stable position upon a flow of a predetermined electrical current through said electrical circuit thereby opening said first and second contact elements and breaking said electrical circuit; and reset means actuable from a first position to a second position to move said resilient bimetallic member from said second stable position to said first stable position wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position.
 11. A relay control for an electrical circuit comprising: a first, second and third insulating means; a first snap action resilient bimetallic member operable between a first stable position and a second stable position wherein said resilient bimetallic member comprises a first leg and a second leg spaced apart from said first leg wherein said first leg and said second leg are electrically insulated from each other at a first end and are electrically connected at a second end; a first resilient conducting member comprising a first end and a second end wherein said first end is electrically insulated from said first bimetallic member by said first insulating means; a stationary conducting member comprising a first end and a second end wherein said first end is secured to said second insulating means and is spaced apart from said first resilient conducting member; a first contact element located on the surface of said stationary conducting member; a second contact element located on the surface of said resilient conducting member wherein said first and second contact elements are electrically connected to said electrical circuit; a second resilient member connected between said second end of said first bimetallic member and said second end of said first resilient conducting member and electricallY insulated therefrom wherein said second resilient member maintains said first resilient bimetallic member in said first stable position whereby said first and second contact elements are electrically closed against each other; first electrical terminal means connected to said first leg of said first bimetallic resilient member and insulated from said stationary conducting member by said first insulating means; second electrical terminal means connected to said second leg of said first bimetallic resilient member and insulated from said first leg by said third insulating means; a source of control current connected to said first and second electrical terminal means wherein said control current causes heat in said first resilient bimetallic member and wherein said heat causes said first resilient bimetallic member to move to said second stable position thereby opening said first and second contact elements and breaking said electrical circuit; and reset means actuable from a first position to a second position to move said first resilient bimetallic member from said second stable position to said first stable position wherein said reset means prevents said first and second contact elements from closing until said reset means returns to said first position. 